U.S. patent application number 13/135915 was filed with the patent office on 2013-01-24 for method and apparatus for a railway wheel ultrasonic testing apparatus.
This patent application is currently assigned to AMSTED Rail Company, Inc.. The applicant listed for this patent is John D. Oliver, John R. Oliver. Invention is credited to John D. Oliver, John R. Oliver.
Application Number | 20130019686 13/135915 |
Document ID | / |
Family ID | 47002510 |
Filed Date | 2013-01-24 |
United States Patent
Application |
20130019686 |
Kind Code |
A1 |
Oliver; John R. ; et
al. |
January 24, 2013 |
Method and apparatus for a railway wheel ultrasonic testing
apparatus
Abstract
A method and apparatus for collecting ultrasonic test data from
a railway wheel with an ultrasonic testing apparatus is described.
The railway wheel is supported by two drive rollers, each having an
indentation which engages with and rotates the wheel. An indexing
transducer moves across the rotating wheel, collecting ultrasonic
test data while a fixed transducer correlates a reference position
on the wheel to the collected test data. To maintain the accuracy
of the reference position to the collected test data, it is
desirable to maintain the rotational stability of the wheel,
minimizing any dynamic instability caused by dimensional tolerances
in the wheel. To mitigate instabilities resulting from dimensional
tolerances, the indentation of the drive rollers, which engage and
drive the flange of the wheel, is adjustable by the flexing design
of the drive rollers to maintain frictional contact between the
wheel and the drive roller. This allows the indentation to
accommodate the varying dimensional tolerances of the wheel flange,
mitigating the possibility of dynamic instability resulting from
departure of the wheel flange from the indentation.
Inventors: |
Oliver; John R.; (Flossmoor,
IL) ; Oliver; John D.; (Flossmoor, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Oliver; John R.
Oliver; John D. |
Flossmoor
Flossmoor |
IL
IL |
US
US |
|
|
Assignee: |
AMSTED Rail Company, Inc.
Chicago
IL
|
Family ID: |
47002510 |
Appl. No.: |
13/135915 |
Filed: |
July 19, 2011 |
Current U.S.
Class: |
73/622 |
Current CPC
Class: |
G01N 29/043 20130101;
B61K 9/12 20130101; G01N 2291/2696 20130101; G01N 29/225 20130101;
G01N 29/27 20130101; G01M 17/10 20130101 |
Class at
Publication: |
73/622 |
International
Class: |
G01N 29/04 20060101
G01N029/04 |
Claims
1. An ultrasonic test fixture for a wheel, comprising: a plurality
of drive rollers for supporting the wheel, wherein at least one of
the plurality of drive rollers comprises: a unitary structure
having a first annular section affixed around a drive shaft, and a
second annular section, the second annular section adjacent to the
first annular section to form an indentation between the first
annular section and the second annular section for engaging the
wheel; the first annular section having a flexibility such that the
indentation between the first annular section and the second
annular section is adjustable to accommodate varying sizes of
wheels, a drive motor connected to the drive shaft to rotate the at
least one of the plurality of drive rollers.
2. The ultrasonic test fixture of claim 1, further comprising a
bore through the first annular section, wherein the fastener
slidingly engages the bore.
3. The ultrasonic test fixture of claim 1, further compromising a
tank.
4. The ultrasonic test fixture of claim 3, further comprising a
frame assembly, wherein the tank is mounted to the frame assembly,
and further wherein the plurality of drive rollers are mounted
inside the tank.
5. The ultrasonic test fixture of claim 3, wherein the plurality of
drive rollers are mounted inside the tank, and further wherein the
tank contains a coupling fluid.
6. The ultrasonic test fixture of claim 4, further comprising a
restraining roller mounted to the frame assembly, the restraining
roller for selectively engaging the wheel to maintain the vertical
orientation of the wheel on the plurality of drive rollers.
7. An ultrasonic test fixture for a wheel, comprising: a plurality
of drive rollers for supporting the wheel, at least one of the
plurality of drive rollers for rotating the wheel, wherein at least
one of the plurality of drive rollers comprises: an inner annular
section affixed to a drive shaft; and an adjacent outer annular
section to form an indentation between the inner annular section
and the outer annular section for engaging the wheel; one of the
annular sections is axially displaceable relative to the other
annular section to vary the indentation and accommodate varying
sizes of wheels, and a drive motor connected to the drive shaft to
rotate at least one of the drive rollers.
8. The ultrasonic test fixture of claim 7, further comprising: a
first bore through the drive roller to accept the drive shaft.
9. The ultrasonic test fixture of claim 7, further compromising a
tank for holding a coupling fluid.
10. The ultrasonic test fixture of claim 7, further comprising a
tank for holding a coupling fluid, wherein at least one of the
drive rollers are mounted inside the tank.
11. The ultrasonic test fixture of claim 9, further comprising a
frame assembly, wherein the tank is mounted to the frame assembly,
and further wherein the plurality of drive rollers are mounted
inside the tank.
12. The ultrasonic test fixture of claim 11, further comprising a
restraining roller mounted to the frame assembly, the restraining
roller for selectively engaging the wheel to maintain the vertical
orientation of the wheel on the plurality of drive rollers.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. Pat. No. 5,864,065,
granted Jan. 26, 1999 to Prorok and entitled, "Test Apparatus for a
Railway Wheel", which is hereby incorporated by reference in its
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to ultrasonic testing, and more
particularly, in one embodiment, to the ultrasonic testing of
railway wheels.
BACKGROUND OF THE INVENTION
[0003] Railway wheels are generally either wrought or cast steel,
and despite strict quality control measures, may contain flaws
resulting from the manufacturing process. These flaws can
potentially include voids, cracks, as well as inclusions, which can
weaken the wheel and potentially lead to wheel failure. Ultrasound
testing has been commonly employed to detect such flaws.
[0004] Railway wheels ultrasonically analyzed by fixed position
transducers typically examine the wheel and its underlying
structure only at discrete, single locations around the perimeter
of the wheel tread face or wheel flange. To obtain a more complete
diagnostic analysis of the entire wheel structure, without the
intensive analysis required by a fixed position transducer, an
automated ultrasonic testing method has been developed.
[0005] Automated ultrasonic testing has been challenged, to some
extent, by the size and weight of railway wheels (typically
weighing from 700 to 1000 pounds) which can make the automated
collection of accurate ultrasonic test data difficult. Particularly
problematic are railway wheels with dimensional tolerances that,
although within an acceptable range for production purposes, hamper
the automated collection of accurate test data.
[0006] In prior art test fixtures, the typical railway wheel may
have dimensional tolerances capable of producing dynamic
instabilities as the wheel is rotationally driven for ultrasonic
examination. These instabilities result in the deflection of the
wheel from axial centerline rotation around the geometric center of
the wheel in the test fixture. This has proven problematic as the
collection of accurate ultrasonic test data often requires
maintaining a stable geometric orientation as the wheel
rotates.
SUMMARY OF THE INVENTION
[0007] A method and apparatus are provided for the application of
automated ultrasonic testing to a railway wheel. To achieve faster
data collection rates, as well as more accurate and reproducible
ultrasonic test data, a novel method and apparatus are presented
for mitigating the oscillations and other dynamic instabilities
resulting from railway wheel rotation in the ultrasonic test
fixture. More specifically, a novel drive assembly in the
ultrasonic test fixture adaptively accommodates dimensional
tolerances in the rotating railway wheel, dampening deflections and
other oscillations that would otherwise potentially affect the
accuracy and reproducibility of ultrasonic test data.
BRIEF DESCRIPTION OF THE FIGURES
[0008] Various embodiments of the ultrasonic testing apparatus are
described and illustrated in the accompanying figures. The figures
are provided as examples only and are not intended to be considered
as limitations to the invention. Consequently, the ultrasonic
testing apparatus and the ultrasonic test fixture are illustrated
by way of example and not by limitation in the accompanying figures
in which:
[0009] FIG. 1 is a cross-sectional, elevation view of an exemplary
embodiment of the ultrasonic testing apparatus;
[0010] FIG. 2 is a cross-sectional, elevation view through section
2-2 of FIG. 1;
[0011] FIG. 3 is a front elevation view of the mounting stand and
encoder assembly of the ultrasonic testing apparatus depicted in
FIG. 1;
[0012] FIG. 4 is a side elevation view of the encoder assembly of
FIG. 3;
[0013] FIG. 5 is one embodiment illustrating a control circuit
schematic for the exemplary ultrasonic testing apparatus of FIG.
1;
[0014] FIG. 6 is a plan view of the ultrasonic testing apparatus
illustrated in FIG. 1;
[0015] FIG. 7 is an elevation view through section 7-7 of FIG.
6;
[0016] FIG. 8 is a plan view of one embodiment of the encoder
assembly;
[0017] FIG. 9 is an isometric view of an exemplary railway
wheel;
[0018] FIG. 10 is an orthographic view of one embodiment of an
exemplary prior art, unitary drive roller;
[0019] FIG. 11 is a cross-sectional view through section 10-10 of
the prior art, unitary drive roller depicted in FIG. 10;
[0020] FIG. 12 is a partial, cross-sectional view of an exemplary
wheel engaging with the exemplary drive roller depicted in FIG.
11;
[0021] FIG. 13 is a cross sectional view of one embodiment of an
exemplary split drive roller;
DETAILED DESCRIPTION
[0022] Although this specification is directed to the testing of
railway wheels, it should be understood that the testing apparatus
and methods disclosed in this specification are equally applicable
to other cast and forged wheels used in industries unrelated to the
railway industry. Consequently, the description of the novel method
and apparatus as it relates to railway wheels is for convenience
only.
[0023] Railway Wheel Ultrasonic Testing Apparatus
[0024] One embodiment of the ultrasonic testing apparatus is
depicted in the front elevation view of FIG. 1 and the side
elevation view of FIG. 2. The ultrasonic testing apparatus is
designed for the nondestructive evaluation and subsurface mapping
of the structure of a railway wheel 100 of the type exemplified by
the illustration of FIG. 9.
[0025] The ultrasonic testing apparatus comprises, in one
embodiment, the ultrasonic test fixture 11 for capturing and
rotating the wheel and the ultrasonic sensing assembly 90. In
addition, a CPU (e.g., a programmable logic circuit (PLC)) (not
shown) may be used, in some embodiments, to coordinate the data
acquisition activities of the ultrasonic sensing assembly 90 with
the wheel handling, transfer, and drive functions performed by the
ultrasonic test fixture 11.
[0026] The ultrasonic testing apparatus 10 may have many different
embodiments that include additional assemblies in various
combinations. For example, the extent to which the handling of the
railway wheel test specimen is automated will affect the number and
types of assemblies required by the test apparatus. In one
embodiment, the testing apparatus 10 may include a number of
optional assemblies to position and rotate the test specimen in the
test fixture 11. These assemblies include, in one embodiment, a
transfer assembly 50, a loading assembly 60, a retaining assembly
120, and a restraining assembly 70; in addition to the drive
assembly 80 for rotating the test specimen. Each assembly is
mounted on, or operable with, in this embodiment, the frame
assembly 12 and the coupling fluid tank 22.
[0027] As noted above, not all the listed assemblies are required
for the collection of ultrasonic test data. For example, in another
embodiment, the wheel 100 is placed into position on the drive
assembly 80 by a manual device such as a crane and hook (not
shown). As a result, the wheel transfer and handling assemblies are
not required in this embodiment; instead, only the frame assembly
12, tank 22, and the drive assembly 80 are required in the test
fixture 11. Consequently, in one embodiment, the testing apparatus
10 may comprise only the frame assembly 12, the drive assembly 80
for rotating the wheel, the tank 22 for immersing the wheel in a
coupling fluid, and the sensing assembly 90 for collecting
ultrasonic test data.
[0028] Other embodiments of the ultrasonic testing apparatus 10 may
include other combinations of assemblies. For example, the tank 22
is not necessary in embodiments where other means for coupling the
ultrasonic transducer to the wheel are used (e.g., direct
transducer contact in lieu of immersion coupling).
[0029] Referring to FIG. 1, the ultrasonic testing apparatus 10
depicts, in one embodiment, an automated system for the collection
of ultrasonic test data. The ultrasonic testing apparatus 10
depicted in FIG. 1 has a frame assembly 12 with upright legs 14,
16, 18 and 20 anchored to the floor 17. A tank 22 for holding
coupling fluid 155 is mounted on legs 14, 16, 18 and 20 at upper
leg ends 15. The tank 22, in one embodiment, is shown with a
rectangular shape in FIGS. 1 and 2. The tank 22 is defined by a
lower wall 23, front sidewall 25 (shown on FIG. 2), rear sidewall
27, first end wall 29, and second end wall 31. The front sidewall
25, rear sidewall 27, first end wall 29, and second end wall 31
form an upper wall edge 33 and enclose a volume 35. Each sidewall
25, 27 and end wall 29, 31 of the tank 22 has a lower flange 37 and
an upper flange 39.
[0030] At the corners 41, the ultrasonic testing apparatus 10 has
upright arms 24, 26, 28 and 30 extending vertically upward from the
tank 22 and upper flanges 39. The upright arms 24, 26, 28 and 30
are connected by horizontal cross braces 36 and 38 at the upper
ends 40 of the frame assembly 12.
[0031] Railway wheels, although generally similar, may be built to
different standards having different dimensions and tolerances. For
example, referring to FIG. 9, a typical railway wheel 100 for use
in conjunction with the ultrasonic testing apparatus is
illustrated. The railway wheel 100 includes a wheel flange 102,
flange face 104, tread face 106, rim face 108, and hub 110 with
axle bore 112.
[0032] Referring back to FIG. 1, a railway wheel 100 is illustrated
in dashed outline format in two different sizes to depict the
general position of the wheel within the ultrasonic testing
apparatus 10. In one embodiment, the ultrasonic testing of a
railway wheel begins with the entrance of the wheel 100, rolling on
its tread face 106, into frame assembly 12 from left to right in a
generally upright manner along a rail track with guide rails (not
shown). The wheel 100 moves on the above noted rail and guides to a
generally central position in the frame assembly 12 above the tank
22 and among the upright arms 24, 26, 28 and 30 to position the
wheel for engagement with the wheel transfer assembly 50.
[0033] As wheel 100 is rolled into position, sensors (not shown)
communicate a signal indicating the position of the wheel 100. When
the wheel reaches a predetermined position in the testing apparatus
10, the lateral retaining assembly 120 is activated, stopping the
wheel over the first and the second wheel runway assemblies 140,
142 of the wheel loading assembly 60.
[0034] Wheel Retaining Assembly
[0035] Referring to FIGS. 6 and 7, the wheel retaining assembly 120
is depicted. The retaining assembly 120 maintains the lateral
position of the wheel 100 on the track during testing. For example,
in one embodiment, retaining rollers 251 in each of two separate
sub-assemblies comprising the retaining assembly 120 are translated
by pneumatic cylinders into both the forward and reverse paths of
wheel travel on the rail to laterally capture the wheel.
[0036] The retaining assembly 120 comprises two separate, but
generally identical, mechanical sub-assemblies for blocking each
side of the wheel: the first and second retaining roller
sub-assemblies 220, 230. The second retaining roller sub-assembly
230, which is in juxtaposed relation to first retaining roller
sub-assembly 220, has a mirror image relationship and operation to
the first retaining roller sub-assembly 220. In this embodiment,
all of the components in the first retaining roller sub-assembly
220 are also present and operate in the same manner as the second
retaining roller sub-assembly 230. Consequently, the description
and operation of the retaining roller sub-assembly 220 is generally
applicable to the operation of the second retaining roller
sub-assembly 230. The operation of one of the two retaining roller
sub-assemblies in the wheel retaining assembly 120 is described as
follows.
[0037] A first retaining roller sub-assembly 220 includes a first
pneumatic retaining cylinder 222 pivotally coupled to an upright
arm 26 with the clevis 224 and first pin 226 at the upper cylinder
end 228 and first eye bracket 229. A reciprocable rod 232 is
extendable from the pneumatic retaining cylinder 222 at the
cylinder lower end 234. A bushing 250 at the second bore 246 has a
pivot arm 236 which is coupled to distal end 233 of the
reciprocable rod 232 by a second female clevis 240 and a second pin
242. This coupling allows pivotal rotation of the pivot arm 236 on
the first pivot shaft 244 (extending through the second bore 246)
by the reciprocable rod 232. The stopper arm 248 is coupled to the
bushing 250 at the first stopper arm end 249 with the retaining
roller 251 secured on the pin 252 at the second stopper arm end
253. Reciprocation of the rod 232 induces rotation of the bushing
250 and the stopper arm 248 to position the retaining roller 251 in
proximity to the wheel 100, capturing the wheel 100 in one
direction of travel along the track.
[0038] In operation, the first and second retaining roller
sub-assemblies 220, 230 act together to block lateral travel of the
wheel 100 on the track within the ultrasonic testing apparatus 10
with the retaining rollers 251 on either side of the wheel. The
retaining roller sub-assemblies 220, 230 are designed to
automatically align the wheel 100 in the test fixture 11 with the
bridge sub-assembly in preparation for the transfer of the wheel to
the loading assembly.
[0039] Wheel Transfer Assembly
[0040] The wheel 100 initially moves onto the wheel transfer
assembly 50, and more specifically, into the downwardly extending
arms 125, 127 and second pin 126 of the bridge sub-assembly 130.
With the wheel 100 retained in place with the wheel retaining
assembly 120, the bridge sub-assembly 130 of the wheel transfer
assembly 50 transfers the wheel 100 into the wheel loading assembly
60. The operation of one embodiment of the wheel transfer assembly
50 and its component parts is described in more detail below.
[0041] The wheel transfer assembly 50 depicted in FIGS. 1 and 2 has
a first upright support 131 and a second upright support 132
downwardly extending from the horizontal brace 38. Upwardly
extending angle brackets 133, 134 are mounted on the rear sidewall
27 and are connected to the upright supports 131, 132 respectively.
Anchoring braces 135 and 136 are positioned on the outer surfaces
of the angle brackets 133, 134 (respectively) with securing bolts
137 extending through braces, brackets, and supports 131 to 136. A
cross pin 138 extends through braces 135, 136 and angle brackets
133, 134 with first and second downwardly extending arms 125 and
127, respectively. Second pin 126 extends between the downwardly
extending arms 125 and 127.
[0042] Wheel transfer assembly 50 in FIGS. 1 and 2 has pneumatic
transfer cylinder 340 secured at its upper end 346 by an eye
bracket 342 of the clevis 344. The eye bracket 342 is mounted on
the first and second upright supports 131 and 132. The connecting
arm 348 is pivotally connected at its first end 349 to the drive
rod 350 at the lower end 352 of the pneumatic transfer cylinder 340
and is drivingly coupled to the cross pin 138 at the lower end 354
of the connecting arm 348.
[0043] After engaging the wheel in position on the bridge
sub-assembly 130, the pneumatic transfer cylinder 340 is actuated
to rotate the bridge assembly 130. This occurs with the extension
of the drive rod 350 by the pneumatic transfer cylinder 340,
rotating the connecting arm 348 and cross pin 138, which
consequently rotates the downwardly extending arms 125 and 127
about the pin axis 139, and thereby deposits the wheel 100 on, or
captures wheel from, the wheel loading assembly 60. This locates
the wheel 100 on the first and second wheel runway sub-assemblies
140, 142 of the wheel loading assembly 60.
[0044] Wheel Loading Assembly
[0045] After the wheel transfer assembly 50 has positioned the
wheel 100 for engagement with the first and second wheel runway
sub-assemblies 140, 142, the wheel loading assembly 60 lowers the
wheel 100 to engage with the drive rollers 150, 152 of the drive
assembly 80. The wheel runway sub-assemblies in the wheel loading
assembly 60 are part of two separate and independent sub-assemblies
comprising the wheel loading assembly 60. These two sub-assemblies
are generally identical in structure and operation, juxtaposed on
either side of the wheel in the test fixture 11. Because the two
wheel runway sub-assemblies 140, 142 operate similarly, as though
mirror images, only the structure and operation of wheel runway
sub-assembly 140 will be described.
[0046] One embodiment of the wheel loading assembly 60 is
illustrated in FIG. 1. In this embodiment, the wheel is supported
by the loading rollers 145, 146 in both wheel runway sub-assemblies
140 and 142. The wheel runway sub-assemblies 140, 142 are
immediately adjacent and equally support the wheel 100 centered
above the runway sub-assemblies. The wheel runway sub-assemblies
140, 142 rotatably pivot downward in an arc to lower the wheel 100
between the runway sub-assemblies onto the drive rollers of the
drive assembly 80.
[0047] The operation of the wheel runway sub-assembly 140 is
powered by a pneumatic loading cylinder 300. The pneumatic loading
cylinder 300 is pivotally coupled to the upright arm 24 with a
clevis 302 and pin 304 at the upper cylinder end 306 and the third
eye bracket 308. A reciprocable rod 310 with a distal end 314 is
extendable from the lower end 312 of the pneumatic loading cylinder
300 and is coupled to the pivot arm 316 at the pivot arm end 322 by
a bushing 320 and a pin 324. The pivot arm 316 at its second end
319 is secured to a bushing 318 on the first pivot shaft 244 at its
second end.
[0048] The first wheel runway sub-assembly 140 in FIG. 1 has a
runway arm 144 with a first loading roller 145 and a second loading
roller 146 at its distal end 147. The runway arm 144 is also
secured to the first pivot shaft 244 and is rotatable by movement
of the pivot arm 316 to align the loading rollers 145, 146 with the
track (not shown) to receive wheel 100.
[0049] Similarly, the second wheel runway sub-assembly 142 has a
second set of loading rollers 145, 146 to receive and transfer the
wheel 100 either into or out of the ultrasonic testing apparatus
10. As noted above, the second wheel runway sub-assembly 142 is
juxtaposed to the first wheel runway assembly 140, consequently,
the direction of rotation of the reciprocating shafts and pivoting
of the several components are mirror images of the direction of
movement of the components of the wheel runway sub-assembly
140.
[0050] Using the wheel loading assembly 60, the first and second
loading rollers 145, 146 of wheel runway sub-assemblies 140 and 142
lower the wheel 100 onto the drive rollers 150, 152 (see FIG. 6) of
the drive assembly 80. Thereafter, the wheel runway sub-assemblies
140, 142 are moved away from contact with the wheel 100. The wheel
runway sub-assemblies 140, 142 are rotated away from the wheel 100
by extending the rods 310 from the pneumatic loading cylinders 300,
which move pivot arms 316 on first pivot shaft 244 away from the
wheel.
[0051] Wheel Vertical Restraining Assembly
[0052] In addition to restraining the lateral motion of the wheel
100 in the testing apparatus 10, it is also desirable, in certain
embodiments, to support the upper portion of the wheel 100 to
prevent an overturning moment. The wheel vertical restraining
assembly 70 performs this function.
[0053] Referring to FIG. 2, after the wheel 100 is transferred to
the loading assembly 60, the wheel vertical restraining assembly 70
is in position to capture the top of the wheel 100 in the
indentation 362 of the restraining roller 360. The restraining
roller 360 is mounted on the distal end 364 of the rod 366 and is
moved into position at the upper end of the wheel 100 in the frame
assembly 12 by extending the rod 366 from the pneumatic restraining
cylinder 370. The pneumatic restraining cylinder 370 is mounted
generally between cross-braces 32, 34, 36 to 38 at the upper end 40
of the frame assembly 12. The indentation 362 of the restraining
roller 360 captures the top end of the wheel 100 within the frame
assembly 12, maintaining the wheel in an upright position during
the test cycle.
[0054] The wheel 100 is now, in this embodiment, captured both
vertically and laterally (on the track). With the wheel 100 in
engagement with the first and second drive rollers 150, 152, the
drive assembly 80 is available to rotate the drive rollers 150,
152, and in turn, rotate the wheel 100.
[0055] Wheel Drive Assembly
[0056] Referring to FIGS. 2 and 6, the drive assembly 80 includes
the first and second drive rollers 150, 152 which, in one
embodiment, are positioned in the tank 22 below the fluid surface
154 of the coupling fluid 155. The first drive roller 150 and
second drive roller 152 each have an arcuate indentation 190, 192,
respectively, on each drive roller circumference. The indentations
190, 192 of the first drive roller 150 and the second drive roller
152 are aligned to engage a portion of the wheel flange of the
wheel 100 during testing. The indentations 190, 192 engage with the
wheel flange 102 to rotate the wheel 100.
[0057] The first drive roller 150 is mounted on the first end 156
of the first drive shaft 158. The first drive shaft 158 extends
through the first aperture 160 and the first seal 162 in the rear
sidewall 27 of the tank 22 and through the first and the second
pillow block and bearing 164, 166 respectively. The first and the
second pillow block and bearing 164, 166 are mounted on the bearing
plate 168, which is secured to the frame assembly 12. Affixed to
the first drive shaft 158 is a first driven sprocket 170 mounted on
the second end 172 of the first drive shaft 158.
[0058] Juxtaposed to the first drive roller 150 is the second drive
roller 152 on the first end 180 of the second drive shaft 174. The
second drive shaft 174 in FIG. 6 is generally parallel to the first
drive shaft 158 and extends through the second aperture 176 and
seal 178 in the tank 22. Second drive shaft 174 continues to extend
through the third and forth pillow block and bearing 182 and 184
respectively. The third and fourth pillow block and bearing 182 and
184 are mounted on bearing plate 168. Affixed to the second drive
shaft 174 is a second driven sprocket 186 (shown on FIG. 1) mounted
on the second end 188 of the second drive shaft.
[0059] Referring back to FIG. 1, the wheel drive assembly 80 also
includes drive chain 198 which extends between the first driven
sprocket 170 and the driver sprocket 200. The driver sprocket 200
is affixed to the motor shaft 202 extending from the drive motor
204. Similarly, the second drive chain 206 extends between the
driver sprocket 200 and the second driven sprocket 186. The wheel
100 may be rotated by driving rotation of any or both the first
driven sprocket 170 or the second driven sprocket 186 from the
drive motor 204 rotating the driver sprocket 200 and connecting
drive chains 198, 206.
[0060] In an alternate embodiment a second drive motor (not shown)
with a separate drive sprocket (not shown) may be utilized for
independent coupling to the second driven sprocket 186. Other types
of drives could also be provided; including, for example, belts and
sheaves, and gear drives. Alternatively, in another embodiment,
second driven sprocket 186 and second drive shaft 174 may act as an
idler or roller without direct coupling to a drive motor; using the
second roller 152 as an idler for wheel support only.
[0061] Referring to FIG. 10, an orthographic view of an exemplary
embodiment of a prior art, drive roller 150 is illustrated having a
plurality of shaft fastener bores 151. The shaft fastener bores
align with bores in the drive shaft (not shown) to allow the drive
roller 150, in this embodiment, to be affixed to the drive shaft
with threaded fasteners (not shown).
[0062] Referring to FIG. 11, a cross-sectional view of the drive
roller 150 depicted in FIG. 10 is illustrated. An indentation 190
for capturing the wheel flange of the wheel is formed around the
circumference of the drive roller 150. In the embodiment
illustrated in FIGS. 10 and 11, the drive roller 150 is a unitary
component.
[0063] Referring to FIG. 12, the engagement of the wheel 100 with
the indentation 190 of the drive roller 150 is illustrated. The
drive roller 150 imparts rotational motion to the wheel 100 through
frictional interaction between the indentation 190 of the drive
roller 150 and the wheel flange 102 captured in the indentation.
This frictional fit and the effectiveness of the ultrasonic testing
apparatus 10 in general, are highly dependent upon the dimensional
tolerances of the wheel 100.
[0064] In practice, large variations in the dimensional tolerances
of the wheel 100, particularly at high rotational velocities, may
create dynamic instabilities causing the wheel 100 to depart from
the indentations in the drive rollers. Data collection accuracy is
degraded as a result of instabilities in rotational motion produced
by the erratic movement of the wheel. To mitigate oscillations and
dynamic instabilities resulting from dimensional tolerances in the
wheel, an alternative and novel embodiment of the drive rollers is
described below.
[0065] Referring to FIG. 13, a cross-sectional view of an exemplary
and novel drive roller embodiment (referred to hereinafter as a
drive roller 500) is illustrated. The drive roller 500, in one
embodiment, is comprised of a single piece structure 510 which is
fitted on the end of drive shaft 158.
[0066] Drive roller structure 510 is itself comprised of an inner
annular section 520 and an outer annular section 530. A gap 591 is
formed between inner annular section 520 and outer annular section
530. Flange 102 of railway wheel 100 is fitted into gap 591. Inner
annular section 520 may include a cutout area 515 which reduces the
rigidity of a inner annular section 520 to allow inner annular
section 520 to flex and adjust the width of gap 591 to accommodate
varying sizes and design of railway wheel flanges 102. Drive roller
structure 510 may be comprised of a steel or a structural plastic;
in either case being designed to have adequate strength and wear
resistance to impact rotation to railway wheel 100 while having a
long service life.
[0067] Ultrasonic Sensing Assembly
[0068] Referring to FIG. 5, a control schematic 400 of the
ultrasonic testing apparatus control system is illustrated which
includes, in one embodiment, the ultrasonic sensing assembly 90.
The ultrasonic sensing assembly 90 comprises, in one embodiment,
the ultrasonic test unit, transducers, and encoder assembly for
transmitting and receiving, as well as processing ultrasonic
signals.
[0069] Ultrasonic Transducers
[0070] Ultrasonic transducers transmit ultrasonic signals to the
test specimen (i.e., the wheel 100) and receive reflected
ultrasonic signals. The reflected ultrasonic signals provide the
data necessary to allow analysis and detection of substructure
flaws in the wheel. In one embodiment of the ultrasonic sensing
assembly 90, two transducers may work together to map the position
of flaws in the test specimen.
[0071] A fixed transducer 414 is provided in a fixed location in
close proximity to the wheel rim face 108 as noted in FIG. 4 to
provide a reference position. The other transducer is an indexing
transducer 416 which moves relative to the wheel 100 in close
proximity to the tread face 106. To move the indexing transducer
416 relative to the wheel 100, an encoder assembly 402 is used to
move the indexing transducer 416 in fixed increments to traverse
the wheel 100.
[0072] Encoder Assembly
[0073] In this embodiment, the encoder assembly 402 (as illustrated
in FIGS. 3, 4, and 8) is affixed to mounting stand 404 and
functions to move and record the position of the indexing
transducer 416 as it moves incrementally across the wheel in
discrete steps. The encoder assembly synchronizes data acquisition
with the indexing transducer's position, allowing the ultrasonic
testing apparatus to accurately identify the location and the
dimensions of defects found in the scan. Encoder assembly 402
includes the transducer drive motors 406, 408; control table 410;
and transducer arm 412. Each of these components of the encoder
assembly 402 are described below in more detail.
[0074] Transducer Drive Motors
[0075] The mounting stand 404 to which the encoder assembly 402 is
attached, is anchored to the floor 17 as noted in FIGS. 2 and 3.
The encoder assembly 402 is affixed to the mounting stand 404
(above the pillow blocks and bearings 164, 166, 182, and 184) with
first or x-direction transducer drive motor 406 and second or
y-direction transducer drive motor 408 secured to the control table
410 at the top of the mounting stand 404. In this configuration,
the control table 410 and the transducer arm 412 are movable in the
x direction by the first transducer drive motor 406 (horizontally
along the plane as noted in FIG. 4). Similarly, a second transducer
drive motor 408 is operable to move the control table 410 in the
y-direction as noted in FIG. 3. The transducer drive motors 406,
408 may be, in one embodiment, micro-stepper motors.
[0076] Referring to FIG. 4, the transducer arm 412 is driven by the
control table 410. At its distal end, the transducer arm 412 has an
indexing transducer 416. The transducer arm 412, in this
embodiment, has a generally L-shaped form extending downwardly into
the coupling fluid 155 of tank 22. The indexing transducer 416 is
driven in incremental steps by the transducer drive motors 406, 408
through the control table 410 and transducer arm 412. With the
indexing transducer 416 controlled by the encoder assembly 402 and
the fixed transducer 414 positioned adjacent to the wheel, the
transducers are ready to transmit and receive ultrasonic signals
under the control of the ultrasonic test unit.
[0077] Ultrasonic Testing Unit
[0078] Referring back to FIG. 5, the ultrasonic test unit 451, in
one embodiment, controls the transducers 414, 416 including the
frequency, voltage (or more generally the power of the ultrasonic
signal emitted by the transducer), pulse repetition rates, filter
selections, etc. The ultrasonic testing unit 451 also receives
ultrasonic test data from the transducers 414, 416.
[0079] In one embodiment, the ultrasonic test unit 451 also
provides input and output ports (e.g., USB ports) to provide
communication capabilities directly to a personal computer 470
which is connected to a printer 480. The personal computer 470
functions as a workstation for the operator, allowing the
monitoring of data collection as well as providing the capability
to perform further analysis on the collected data. The personal
computer 470 may include software for processing collected data,
provide alarm monitoring functions, as well as advanced imaging
functions for displaying the ultrasonic data.
[0080] For example, in one embodiment, fixed transducer 414
communicates a signal to ultrasonic test unit 451 through line 452,
which is further communicated and stored in the personal computer
470 through line 471. Similarly, indexing transducer 416
communicates a signal to the ultrasonic test unit 451 through line
454, which is also communicated and stored in the personal computer
470 for comparison and evaluation through line 471.
[0081] Ultrasonic Testing Apparatus Control
[0082] The electrical control schematic depicted in FIG. 5
illustrates one embodiment of the operation and control of the
ultrasonic testing apparatus 10. The ultrasonic testing apparatus
10 has an ultrasonic sensing assembly 90 operating in cooperation
with a CPU 450 which coordinates the ultrasonic sensing assembly 90
with the wheel handling capabilities of the ultrasonic test fixture
11 (through control of the pneumatic cylinders).
[0083] For example, in some embodiments, CPU 450 is operable as a
programmable logic controller (PLC) to provide control signals
through lines 456 to the pneumatic cylinders of ultrasonic test
fixture 11 for delivery and transfer of wheel 100 to and from frame
assembly 12. These pneumatic cylinders are present in the lateral
retaining assembly, the vertical restraining assembly, the transfer
assembly, and the loading assembly. CPU 450 controls each of the
pneumatic cylinders in the above assemblies to position the wheel
in the testing apparatus 10. A number of position sensors (not
shown), in communication with CPU 450, trigger the appropriate
handling sequence in the CPU 450 as the wheel 100 is initially
positioned in the test fixture 11. The ultrasonic testing apparatus
10 is controlled by software programming executed by CPU 450.
[0084] In other embodiments, however, the drive assembly may be the
only wheel handling mechanism present in the ultrasonic testing
apparatus (i.e., no pneumatic cylinder controls are necessary). In
some embodiments, the CPU 450 is still required to control the
encoder assembly 402, indexing transducer 416, as well as the
transducer drive motors 406, 408. Consequently, the CPU 450 is also
part of the ultrasonic sensing assembly 90 in some embodiments.
[0085] In addition to controlling the pneumatic cylinders, the CPU
450 also controls the operation of the drive motor 204 in the drive
assembly 80 to rotate the test specimen. Once the test specimen is
engaged with the drive assembly 80, the CPU 450 may also, in one
embodiment, communicate control signals through line 458 to start
drive motor 204 for timed rotation of wheel 100 in frame assembly
12.
[0086] CPU 450, in one embodiment, also coordinates control of
portions of the ultrasonic sensing assembly 90, including the
encoder assembly for indexing transducer 416. In this embodiment,
CPU 450 may provide control signals to transducer drive motors 406
and 408 through line 460 to index transducer 416. In still other
embodiments, the encoder assembly 402 and the CPU 450 are not
necessary in non-automated, ultrasonic data collection
activities.
[0087] The signal from the fixed transducer 414 provides a
reference point for noting the relative location of the defects in
the wheel 100 which are recorded with indexing transducer 416. In
one embodiment, signals from the indexing transducer 416 and the
fixed transducer 414 may be communicated through lines 454 and 452
respectively to the CPU 450 through lines 455 and 453 to assist in
the control of the test fixture 11 and the appropriate handling and
transfer of the wheel.
[0088] Phase Array Ultrasonic Testing
[0089] If desired, more advanced ultrasonic test instrumentation
may be used, including, phase array ultrasonic testing. In one
embodiment, the ultrasonic test unit 451 may be a phase array
ultrasonic unit, capable of more precise control of transmitted and
received ultrasonic signals from a phase array transducer. In one
embodiment, the phase array ultrasonic unit includes a
pulser/receiver board (not shown) for transmitting and receiving
ultrasonic signals and a multiplexer (not shown) for addressing the
multi-element, phase transducers (not shown).
[0090] The phase array transducers have multi-element construction
to allow the ultrasonic test unit 451 to individually address and
activate specific elements in the transducer to produce a
dynamically controlled aperture having a calculated distribution of
individually activated elements. These programmable apertures are
customized for each region of interest in the test specimen,
providing the capability to focus ultrasonic energy at an angle and
depth in a way that maximizes the clarity of the visual
representation of the test specimen in that region. A transmitting
phase array transducer (i.e., a transmitting aperture) and a
receiving phase array transducer (i.e., a receiving aperture) may
work together with independently selected receiving and
transmitting angles at a predetermined focal length to develop the
image desired in the test specimen at the region of interest.
[0091] Baseline Data Collection
[0092] Initial set-up of the CPU 450 and the ultrasonic test unit
451 includes the development of a baseline ultrasonic test
measurement of a reference wheel having the same size as the wheels
to be tested. The data collected from the reference railway wheel
provides a baseline set of empirical reference parameters for the
comparison and evaluation of test data collected with the
transducers 414, 416 from the test specimen.
[0093] Test Specimen Data Collection
[0094] Wheel 100, supported on the drive rollers 150, 152, is in
position for test and evaluation of the subsurface of the wheel
tread face 106. In this position, the wheel 100 may be rotated as
noted above by actuation of the drive motor 204.
[0095] Initially the relative position of the second or indexing
transducer 416, in one embodiment, is set by a signal sensed by the
first or fixed transducer 414 on the rim face 108 in FIG. 4. This
relative position signal is communicated to the CPU 450 from the
ultrasonic test unit 451 on line 452 and is utilized to compare the
rim face 108 to the reference wheel data to position second
transducer 416. The position of the second or indexing transducer
416 is based upon the baseline empirical data from the reference
wheel. This evaluation then locates the centerline 118 of tread
face 106, which determines the travel distance of the indexing
transducer 416 from the rim face 108 toward the wheel flange
102.
[0096] However, in this embodiment, the second or indexing
transducer 416 is displaced from the horizontal by an acute angle
"a" in FIG. 4. The acute angle "a" is the slope of the angular
displacement of the tread face 106 from a horizontal plane. This
slope or taper is thereby accommodated by the test fixture to
maintain the indexing transducer 416 at a normal or facing
relationship to the tread face 106.
[0097] In one embodiment, the initial position of the transducer
416 is a displacement from the rim face 108 toward centerline 118
(see FIG. 2) of the wheel 100. Thereafter, the wheel 100 is rotated
with drive rollers 150, 152. As the wheel 100 rotates, a transducer
drive motor 406, in one embodiment, incrementally indexes the
indexing transducer 416 toward the wheel flange 102. The transducer
drive motor 406 moves the arm 412 and with it, the indexing
transducer 416.
[0098] In one embodiment, the transducer 416 is indexed along the
tread face 106 from the rim face 108 to the wheel flange 102 at a
rate of approximately 0.075 inches of lateral travel per wheel
revolution, providing a travel range of about 0.675 inches along
the surface of the tread face 106. In one embodiment, the wheel 100
is rotated through nine revolutions at a predetermined rate. The
number of wheel revolutions, however, may be varied by the operator
to accommodate wheel size variations or other variables.
[0099] As the indexing transducer indexes over the wheel, an
ultrasonic signal is communicated through the coupling fluid 155 in
the tank 22 to the tread face 106 to analyze the subsurface for
various discontinuities or flaws such as cracks, voids, and
inclusions. Any of the above anomalies may result in a
discontinuity exemplified by the presence of a reflected signal
detected by the indexing transducer 416.
[0100] The reflected signal, which may be analogized to a reflected
radar signal, provides a comparative signal to the baseline
empirical data. Failure of the signal to provide indication of a
sound wheel structure may result in further testing and evaluation,
repair, or rejection of the wheel as scrap. In the case of a signal
in excess of a predetermined value, the computer can provide an
alarm or other signal to indicate an unacceptable product or
indicate the requirement for rerunning the test.
[0101] The test apparatus described above, in one embodiment,
tracks the precise location of any discontinuities by recording a
reference position on the wheel. With this data, the novel testing
apparatus not only provides a practical means to provide a
comprehensive test of the tread face, but also a methodology for
developing a predictive maintenance program using a historical
database of ultrasonic signatures to detect incipient failures.
Furthermore, the novel testing apparatus provides an opportunity to
evaluate newly manufactured railway wheels to verify the structural
integrity, as well as providing a check on the effectiveness of the
quality control processes implemented during the manufacturing
process.
[0102] While the invention has been illustrated with respect to
several specific embodiments, these embodiments are illustrative
rather than limiting. Various modifications and additions could be
made to each of these embodiments as will be apparent to those
skilled in the art. Accordingly, the invention should not be
limited by the above description or of the specific embodiments
provided as examples. Rather, the invention should be defined only
by the wing claims.
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